This invention includes a method and apparatus for finding a missing remote control unit, especially a unit which controls a television (TV) set or video-cassette recorder (VCR).
It is known to use remote control units to control the operations of electronic appliances such as TV sets and VCRs. Such remote control units are typically wireless, and operate by generating electromagnetic or acoustic waves which are detected by a receiver located inside the appliance. Remote control units are usually designed to be hand-held, and therefore are relatively small. Because of their small size, these units are easily lost or misplaced. A remote control unit for a TV set is often lost in the cushions of a sofa, or under the sheets or blankets of a bed. The unit can also be inadvertently carried away from the site of the TV set.
The problem of locating a missing remote control unit for a television receiver was recognized in U.S. Pat. No. 4,386,371. The solution proposed in the latter patent is to connect the remote control unit to the TV set by a wire. While this approach does solve the problem of locating the remote control unit, it is inconvenient to maintain a wire connection between the remote control unit and the TV set.
It has been known to locate a missing object by using a radio signal to activate an alarm device placed on the object. For example, U.S. Pat. No. 4,101,873 shows a device for locating missing articles, such as eyeglasses or purses. A small transmitter is worn by the user, and a small receiver is attached to the object to be located. The receiver is connected to actuate an alarm. When the transmitter is activated, its signal is detected by the receiver, and the alarm is sounded, giving the user an indication of the location of the object.
U.S. Pat. No. 4,476,469 shows a hand-held device which houses a transmitter, and which causes a receiver, placed on the object to be located, to sound an alarm.
Other patents which describe systems for sounding an alarm to locate missing articles include U.S. Pat. Nos. 4,507,653, 4,598,272, and 4,591,835. All of the above-cited patents are hereby incorporated by reference into this disclosure.
The most pertinent item of the prior art is Japanese Patent Publication No. 63-314994. The latter reference shows a remote control device which receives a signal sent by a transmitter located in the housing of an appliance. Upon detection of the signal, the remote control device sounds an audible alarm.
Although the problem of locating missing articles has been addressed in the prior art, practical problems remain. For example, prolonged operation of the receiver in the remote control unit drains the battery relatively quickly. To assure reliable operation, one must have confidence that the battery powering the receiver will continue to work for a long time. Otherwise, when the remote control device is lost, there will be no easy way of finding it. Also, the remote control devices of the prior art give no indication of how close the user is; merely sounding an alarm may not be enough to tell the user the location of the missing unit. The present invention addresses this and other problems, by providing a convenient and economical improvement over the devices of the prior art.